How to Import Subscriber Phone Numbers
This guide walks you through how to import subscriber phone numbers into Sender for the first time, so your contacts are ready for SMS campaigns.
Where to Find This Feature
In the Sender dashboard, go to: Subscribers → Subscribers → Add subscribers
This opens the Import subscribers page, where you can upload a file containing subscriber data including phone numbers. You will see four import methods at the top of the page: Import from a file, Copy/Paste subscriber list, Import from Mailchimp, and Import from GetResponse. Below the import method tabs, you will find a file upload area, a list format example, and template download options.
Steps to Import Subscriber Phone Numbers
Step 1 — Prepare Your File
Before uploading, format your file so that each subscriber is on a separate row and each field (email, first name, last name, phone number) is in a separate column. Phone numbers must be in international format with the country code prefix (e.g., +1 for the United States, +44 for the United Kingdom). For example: +12345678901.
Sender accepts .csv, .txt, and .xlsx (MS Excel) files up to 64 MB. You can click Download Excel template or Download CSV template on the import page to get a pre-formatted file to work with.
Step 2 — Upload Your File
On the Import subscribers page, make sure the Import from a file tab is selected. Drag and drop your file into the upload area, or click the Import file button to select a file from your computer. Sender will process the file and display a preview of your data in the next step.
Step 3 — Map Columns to Subscriber Fields
After uploading, Sender displays the Match the columns section with a preview of your data. Each column has a dropdown at the top. Verify that Sender has correctly matched your columns to the right subscriber fields — particularly that your phone number column is mapped to Phone number.
If a column is not matched correctly, click the dropdown and select the correct field. You can also search for a field by name, select Create a new field if you need a custom field, or choose Skip this column to exclude a column from the import. A count at the bottom shows how many subscribers will be imported.
Step 4 — Assign to a Group and Start the Import
Below the column mapping preview, you will see the Add subscribers to a group section. Click the Choose groups dropdown to assign imported subscribers to one or more existing groups, or select Create a new group to make a new one. Assigning subscribers to a group makes it easier to target them later in SMS campaigns.
When everything looks correct, click the Start import button. Sender processes the import and returns you to the Subscribers list, where you can verify that the new subscribers and their phone numbers appear.
SMS Compliance Requirements
Consent (TCPA / GDPR) — Before importing phone numbers, you must have explicit opt-in consent from each subscriber to receive SMS marketing messages. In the United States, the Telephone Consumer Protection Act (TCPA) requires prior express written consent. In the European Union, the General Data Protection Regulation (GDPR) requires a clear legal basis for processing personal data, including phone numbers. Only import phone numbers for contacts who have given you verifiable permission.
Phone number format — Sender requires phone numbers in international format, which includes the country code prefix followed by the subscriber’s number (e.g., +14155551234). Numbers that do not include the country code may not be recognized correctly and will not be usable for SMS sending.
Opt-out instructions — Most carrier regulations and Sender’s own SMS policies require every marketing SMS to include opt-out instructions, such as “Reply STOP to unsubscribe.” While this requirement applies when sending messages rather than during import, ensure your imported list only contains subscribers who have not previously opted out.
Purchased or rented lists — Do not import phone numbers from purchased, rented, or scraped lists. Sending SMS messages to contacts who have not opted in violates carrier policies and SMS regulations, and may result in account suspension.
Always consult a legal professional for guidance specific to your jurisdiction and business.
What Happens Next
After importing, go to Subscribers → Subscribers and click on any imported contact to view their profile. The subscriber profile displays an SMS campaign section showing the imported phone number with its status (e.g., ACTIVE). The Subscriber activity log on the right side of the profile confirms the import with entries such as “Phone set to [number] — Source: Import.”
Imported subscribers with valid phone numbers are immediately available for SMS campaigns. To verify your setup, you can send a test SMS to your own number by creating a new SMS campaign from SMS campaigns → New campaign.
You can manage subscriber phone numbers, group assignments, and field mappings at any time from the Subscribers section of the dashboard.
Common Issues
Phone numbers not appearing after import → The phone number column was not mapped to the Phone number field during the column matching step. Re-import the file and make sure the dropdown above the phone number column is set to Phone number.
Phone numbers in incorrect format → Numbers missing the country code prefix (e.g., 5551234567 instead of +15551234567) may not be recognized. Update your file so every phone number starts with + followed by the country code, then re-import.
Subscribers not showing as SMS-active → If a subscriber’s profile shows the SMS campaign section but the phone number is missing or the status is not ACTIVE, the phone number may have been formatted incorrectly or the column was skipped during import. Check the subscriber’s profile and edit the phone number manually if needed.
File upload fails → Sender supports .csv, .txt, and .xlsx files up to 64 MB. Make sure your file is in one of these formats and does not exceed the size limit. If the file is too large, split it into smaller batches.
Duplicate subscribers → If a subscriber with the same email address already exists, Sender updates the existing record with the imported data, including the phone number. This does not create duplicate entries.
FAQs
What file formats does Sender accept for importing subscribers?
Sender accepts .csv, .txt, and MS Excel (.xlsx) files. The maximum file size is 64 MB. You can download a pre-formatted template from the Import subscribers page by clicking Download Excel template or Download CSV template.
What phone number format does Sender require?
Phone numbers must be stored in international format with the country code prefix (e.g., +1 for the United States, +44 for the United Kingdom). The full number should start with + followed by the country code and subscriber number, such as +14155551234.
Do I need consent to import subscriber phone numbers?
Yes. SMS regulations like TCPA (US) and GDPR (EU) require explicit consent from recipients before sending marketing SMS. You should only import phone numbers for subscribers who have actively opted in to receive SMS messages from your business. Consult a legal professional for guidance specific to your jurisdiction.
Can I import phone numbers without email addresses?
Sender’s import process uses email addresses as the primary subscriber identifier. Each row in your import file should include an email address along with the phone number to ensure the subscriber record is created or matched correctly.
Can I assign imported subscribers to a group?
Yes. During the import process, the Add subscribers to a group section lets you select one or more existing groups from the Choose groups dropdown, or create a new group by selecting Create a new group. This helps organize your SMS subscribers for targeted campaigns.
What happens if I import a phone number for an existing subscriber?
If the email address in your import file matches an existing subscriber, Sender updates that subscriber’s record with the newly imported phone number. The existing subscriber data is not duplicated.
How do I verify that the phone numbers were imported correctly?
After importing, go to Subscribers → Subscribers and click on a recently imported contact. The subscriber profile will display the phone number under the SMS campaign section, along with its status. The Subscriber activity log will also show a “Phone set to [number] — Source: Import” entry confirming the import.
Are there SMS sending restrictions by country?
Yes. Some countries have specific carrier restrictions on sender IDs, content, or sending hours. Check Sender’s SMS documentation or contact support for details about restrictions in your target countries.